The entire gear set for C2 miniature lathe aka Sieg, Rotwerk, RC6120,...
The gear set includes inch and metric gears.
I also made a 127 tooth gear, which is not a part of sold sets, since it will not fit in the machine,unless you alter the gear train.
Only the 127 tooth gear allows to cut "actual" inch threads on a metric lathe, but the 57 tooth gear is close enough for most cases.
P.S.: I also added a non-standard 39 tooth gear that's handy when turning a 48 tpi thread.
It reduces the error of 0.32 percent when using the 20, 35, 40, 65 combination to 0.06% with the 20, 55, 39, 80 combination.
The gears are layed out using the gear-plugin of InkScape.
Then exported and extruded in OpenScad.